The present invention relates to a component carrier for insertable circuit boards that are equipped with electronic components. The component carrier includes forward and rear module rails provided with rows of equidistant holes and guide rails provided on their upper side with guide grooves for the circuit boards and at their undersides at each end with at least one perpendicularly projecting centering pin that engages in at least one hole of the module rails. The guide rails further include at least one resilient fastening element for clamping them to the module rails.
The present invention is employed on component carriers for insertable circuit boards of any type and size which are equipped with upper and lower parallel guide rails for the circuit boards and are releasably fastened to the module rails.
Guide rails are known which are made of plastic and extend in pairs between the front and rear, and the upper and lower module rails. They are provided with a longitudinal groove for the circuit boards and with centering pins at their undersides with which they are inserted into holes in the module rails. In addition to the centering pins, identically configured fastening elements are provided on both sides permitting fixing of the guide rail to the two module rails. For this purpose, the latter are provided with T-shaped grooves into which the resilient fastening means are able to snap.
Each one of the prior art guide rails, once clamped at its front and rear to the two module rails, constitutes a stable, form locking connection between the front and rear module rail because the centering pins are firmly and tightly clamped into the holes of the module rails. This type of fastening of the guide rails to the module rails requires that the spacing of the module rails is very accurate and there are close manufacturing tolerances for the guide rails. Otherwise there will be considerable difficulties and lost time during assembly. Additionally, this type of fastening is unable to yield to thermal expansions of the guide rails and/or of the component carrier--insofar as the spacing of the front and rear module rails or the length of the guide rails are changed thereby. The changes in length under consideration here due to the influence of the heat dissipated by the electrical components result in bending of the guide rail and of the module rails.